JP7321964B2 - screw press - Google Patents

Description

The present invention relates to a screw press for squeezing a suspension such as sludge to separate liquid from the suspension, and a method of operating the same. Suspensions include pre-concentrated suspensions, concentrated suspensions, and the like.

Conventionally, a screw press has been used as a device for squeezing sludge (suspension) discharged from liquid treatment facilities such as water and sewage treatment plants and night soil treatment plants to separate water from the sludge (that is, dewatering). Are known. This screw press includes a filter cylinder formed of a screen (perforated plate) and a screw arranged inside the filter cylinder. The screw has a screw shaft arranged concentrically with the filter tube, and screw blades fixed to the outer surface of the screw shaft. By rotating the screw blades with a rotating mechanism connected to the screw shaft, the sludge introduced into the filter cylinder is squeezed and dewatered. A back pressure plate for blocking sludge is arranged at the downstream opening end of the filter cylinder. This back pressure plate retains the cake (dehydrated sludge) sent by the rotating screw blades, and the plug ( plug). This plug applies back pressure to the cake that is fed in later, and further compresses the cake, thereby lowering the moisture content of the sludge in the filter cylinder.

Patent Literature 1 discloses a twin screw press. This type of screw press has a first screw and a second screw arranged in series within a filter tube. These first screw and second screw are configured to be rotatable at different speeds by separate driving devices. The second screw rotates at a low speed to retain sludge and form a plug made of cake (dehydrated sludge) in the filter cylinder. This plug applies back pressure to the sludge that is fed later to squeeze the sludge. Thus, the twin-screw screw press can squeeze the sludge in the filter cylinder without providing a back pressure plate.

JP 2018-51582 A

However, since the first screw and the second screw rotate independently, it is difficult to properly control the rotation speed of these two screws. For example, if the rotation speed of the second screw is too high, a plug for squeezing the subsequent sludge will not be formed in the filter cylinder, and cake with a high moisture content will be discharged. On the other hand, if the rotation speed of the second screw is too low, the plug receives high pressure from subsequent sludge and becomes stuck in the filter cylinder.

Accordingly, the present invention provides a screw press capable of rotating the first screw and the second screw at optimum speeds.

In one aspect, a filter cylinder having an inlet into which a suspension is introduced, a first screw and a second screw arranged in the filter cylinder and transporting the suspension in a predetermined transfer direction, and the second A first rotating mechanism that rotates the first screw, a second rotating mechanism that rotates the second screw independently of the first screw, an imaging device that generates an image of the outer surface of the filter tube, and the inlet A level measuring device for measuring the level of the suspension, and an operation control for issuing commands to the first rotating mechanism and the second rotating mechanism to control the rotation speed of the first screw and the rotation speed of the second screw. wherein said second screw is arranged downstream of said first screw in said conveying direction, said motion control unit regulating said suspension level measurement to be maintained within a predetermined range; a screw press configured to control the rotational speed of the first screw so as to determine the rotational speed of the second screw based on the image.

In one aspect, the motion control unit has a storage device storing a model constructed by machine learning, and the motion control unit inputs the image to the model, and calculates the algorithm defined in the model. to determine the rotation speed of the second screw, which is the rotation speed output from the model.

In one aspect, a method of operating a screw press having a first screw and a second screw disposed within a filter barrel, wherein the level of suspension at the inlet of said filter barrel is maintained within a predetermined range. generating an image of the outer surface of the filtering tube; determining the rotation speed of the second screw based on the image; A method of operating a screw press is provided that rotates at a constant rotational speed.

In one aspect, the step of determining the rotation speed of the second screw based on the image includes inputting the image into a model constructed by machine learning and performing calculations according to an algorithm defined in the model; determining the rotation speed of the second screw, which is the rotation speed output from the model;

According to the present invention, the optimum rotation speed of the first screw is determined based on the level of suspension at the inlet, and the optimum rotation speed of the second screw is determined based on the image of the outer surface of the filter tube. be. In determining these rotational speeds, rather than analyzing a large number of parameters and images, judgments are made based on the minimum necessary information of "suspension level measurement value" and "filtration cylinder outer surface image". In terms of equipment, one of the advantages is that it can be controlled easily and at low cost.

1 is a schematic diagram showing one embodiment of a screw press; FIG. It is a schematic diagram which shows an example of the model constructed|assembled by machine learning. It is a figure explaining the operating method of a screw press. It is a figure explaining the operating method of a screw press. It is a figure explaining the operating method of a screw press.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a schematic diagram showing one embodiment of a screw press. The screw press shown in FIG. 1 includes a cylindrical screen casing (filtration cylinder) 1, which is arranged concentrically with the screen casing 1 within the screen casing 1, and sludge, which is an example of a suspension, is transferred in a predetermined manner. A first screw 3 and a second screw 4 that move in direction D, a first rotating mechanism 7 that rotates the first screw 3, and a second rotating mechanism 20 that rotates the second screw 4 independently of the first screw 3. and has.

The screen casing 1 is formed of a screen (perforated plate) such as punching metal. The screen casing 1 has a sludge inlet 2 at its upstream end. Sludge introduced into the screen casing 1 from the inlet 2 is transferred in a predetermined transfer direction D within the screen casing 1 by the rotating first screw 3 and second screw 4 . Further, the screw press has an operation control section 6 that controls operations of the first rotating mechanism 7 and the second rotating mechanism 20 .

The second screw 4 is connected to the first screw 3 so as to be rotatable independently of the first screw 3 . The first screw 3 and the second screw 4 extend through the screen casing 1 and the discharge chute 33 respectively. A discharge chute 33 is connected to the screen casing 1 . A plug cake, which will be described later, is discharged from the screen casing 1 to the discharge chute 33 .

The axial length of the second screw 4 is shorter than the axial length of the first screw. The first screw 3 has a truncated cone-shaped (tapered) first screw shaft 3A whose diameter gradually increases toward the downstream side in the sludge transfer direction D, and is fixed to the outer surface of the first screw shaft 3A. and a first screw blade 3B. The second screw 4 has a cylindrical second screw shaft 4A and second screw blades 4B fixed to the outer surface of the second screw shaft 4A.

A second screw shaft 4A of the second screw 4 is arranged concentrically with the first screw shaft 3A. The outer diameter of the second screw shaft 4A is the same as the maximum diameter of the first screw shaft 3A. The second screw shaft 4A extends through the wall 33A of the discharge chute 33. As shown in FIG.

The upstream end of the screen casing 1 is sealed by a closing wall 8 . One end (the upstream end in the transfer direction D) of the first screw shaft 3A extends through the closing wall 8 . A water sealing device 10 is installed on the closing wall 8 to seal the gap between the closing wall 8 and the first screw shaft 3A.

The upstream end of the first screw shaft 3A is connected to a first rotating mechanism 7 for rotating the first screw 3. As shown in FIG. A downstream end of the second screw shaft 4A is connected to a second rotating mechanism 20 for rotating the second screw 4 . The specific configurations of the first rotating mechanism 7 and the second rotating mechanism 20 are not particularly limited. For example, each of the first rotating mechanism 7 and the second rotating mechanism 20 may comprise a combination of an electric motor and a torque transmission mechanism (eg, sprocket and chain, or gear and slewing bearing).

The first rotating mechanism 7 has an electric motor (not shown) having an inverter capable of changing the rotation speed and rotation direction of the first screw 3 as a drive source. The second rotating mechanism 20 also has an electric motor (not shown) having an inverter capable of changing the rotation speed and rotation direction of the second screw 4 as a drive source. The motion control unit 6 is configured to be able to control the rotation speed and rotation direction of the first rotation mechanism 7 and the second rotation mechanism 20 . The second rotating mechanism 20 can rotate the second screw 4 independently of the first screw 3 .

The first screw blade 3B extends spirally along the axial direction of the first screw shaft 3A, and the second screw blade 4B extends spirally along the axial direction of the second screw shaft 4A. The total length of the portion of the first screw 3 to which the first screw blades 3B are fixed and the portion of the second screw 4 to which the second screw blades 4B are fixed is the axial length of the screen casing 1. Identical or longer.

A minute gap is formed between the inner surface of the screen casing 1 and the first screw blade 3B, so that the first screw blade 3B can rotate without contacting the screen casing 1. Similarly, a minute gap is formed between the inner surface of the screen casing 1 and the second screw blade 4B, so that the second screw blade 4B can rotate without contacting the screen casing 1. ing. Sludge introduced into the screen casing 1 from the inlet 2 formed at the upstream end of the screen casing 1 is directed toward the discharge chute 33 by the rotating first screw blades 3B and second screw blades 4B (that is, transfer direction D).

In this embodiment, the winding direction (that is, spiral direction) of the second screw blade 4B is opposite to the winding direction of the first screw blade 3B. Therefore, when the sludge input from the input port 2 is sent to the discharge chute 33, the second screw 4 is rotated in the direction opposite to that of the first screw 3, as shown in FIG.

The winding direction of the second screw blade 4B may be the same as the winding direction of the first screw blade 3B. In this case, the second screw 4 is rotated in the same direction as the first screw 3 when sending out the sludge introduced from the inlet 2 to the discharge chute 33 .

As shown in FIG. 1, the screen casing 1 is divided into a dewatering area 1A in which the first screw 3 is arranged and a plug forming area 1B in which the second screw 4 is arranged. A space in which sludge is transferred in the dewatering area 1A is formed by the inner surface of the screen casing 1, the first screw blades 3B, and the first screw shaft 3A. The cross-sectional area of this transfer space gradually decreases along the sludge transfer direction D, as shown in FIG. Therefore, as the sludge introduced from the inlet 2 is transferred through this transfer space by the first screw blade 3B, the sludge is compressed and dewatered. Filtrate that has passed through the screen (perforated plate) of the screen casing 1 is collected by a filtrate receiver 38 arranged below the screen casing 1 . A drain 39 is connected to the filtrate receiver 38 , and the filtrate collected by the filtrate receiver 38 is discharged from the screw press via the drain 39 .

A space in which sludge is transferred in the plug forming area 1B is formed by the inner surface of the screen casing 1, the second screw blades 4B and the second screw shaft 4A. As shown in FIG. 1, the cross-sectional area of this transfer space is constant. In the plug forming area 1B, a plug cake is formed by the sludge (that is, cake) dewatered in the dewatering area 1A.

A screw press with a first screw 3 and a second screw 4 that can rotate independently of each other can form a plug cake in the screen casing 1 without using a back pressure member. Therefore, the screw press of this embodiment does not have a back pressure member such as a back pressure plate for applying back pressure to the plug cake. The method of forming the plug cake is detailed.

The screw press is further equipped with a level gauge 40 for measuring the sludge level (ie surface height) at the inlet 2 of the screen casing 1 . A level measuring device 40 is arranged above the inlet 2 and faces the inside of the screen casing 1 . Although the specific configuration of the level measuring device 40 is not particularly limited, in one example, the level measuring device 40 may use a non-contact level sensor such as a laser level sensor capable of measuring the sludge level without contact. can.

The level measuring device 40 is connected to the operation control section 6 so that the measured value of the sludge level at the inlet 2 is sent to the operation control section 6 . The operation control unit 6 includes a storage device 6a in which programs are stored, and an arithmetic device 6b that executes calculations according to instructions included in the programs. The storage device 6a includes a main storage device such as a RAM, and an auxiliary storage device such as a hard disk drive (HDD) and a solid state drive (SSD). Examples of the arithmetic unit 6b include a CPU (central processing unit) and a GPU (graphic processing unit). However, the specific configuration of the operation control unit 6 is not limited to these examples.

The motion control unit 6 is configured to control the rotation speed of the first screw 3 based on the measured value of the sludge level (ie, sludge surface height) at the inlet 2 . More specifically, the operation control unit 6 issues a command to the first rotating mechanism 7 so that the measured value of the sludge level at the inlet 2 is maintained within a predetermined range, and the first screw 3 to control the rotation speed of the In one embodiment, the motion controller 6 commands the first rotating mechanism 7 based on the measured sludge level to keep the sludge level at the inlet 2 constant. 3 rotation speed is controlled.

According to this embodiment, the first screw 3 rotates at an optimum rotational speed for the flow rate of sludge introduced into the screen casing 1 , and can feed the sludge toward the second screw 4 .

The screw press is further equipped with an imaging device 50 for producing images of the outer surface of the screen casing 1 . The imaging device 50 is positioned on the side of the screen casing 1 and faces the outer surface of the screen casing 1 . The imaging device 50 is a digital camera that produces a color image, a monochrome image (binary image) or a grayscale image of the outer surface of the screen casing 1 . The imaging device 50 is connected to the operation control section 6 so that an image made up of digital data is sent to the operation control section 6 . The operation control section 6 stores the image in the storage device 6a. Although one imaging device 50 is arranged in this embodiment, a plurality of imaging devices 50 may be arranged along the longitudinal direction of the screen casing 1 . Moreover, either a still image or a moving image may be used as needed, and image data having a thermosensor function may be used.

The operation control unit 6 has a model stored in advance in the storage device 6a. This model is a trained model constructed by machine learning. The motion control unit 6 inputs the image generated by the imaging device 50 into the model, and outputs the rotational speed of the second screw 4 from the model.

FIG. 2 is a schematic diagram showing an example of a model stored in the motion control section 6. As shown in FIG. As shown in FIG. 2, the model is a neural network with an input layer 201 , multiple hidden layers 202 and an output layer 203 . However, the configuration of the model shown in FIG. 2 is an example, and the model is not limited to the example shown in FIG.

The input layer 201 of the model receives pixel data forming an image. Pixel data includes color index values (RGB values, luminance values according to grayscale, numerical values representing white or black, etc.) for each pixel. The motion control unit 6 performs calculations according to an algorithm defined in the neural network, and the output layer 203 of the model outputs numerical values representing the rotation speed of the second screw 4 .

Next, machine learning for constructing a model stored in advance in the motion control unit 6 will be described. First, training data (labeled data) containing a plurality of images of the outer surface of the screen casing 1 and corresponding rotational speeds of the second screw 4 are prepared. The rotation speed of the second screw 4 included in the training data is a so-called correct label.

The rotation speed of the second screw 4 as the correct label is determined as follows. During operation of the screw press, the sludge is squeezed and part of the sludge moves outward through the screen casing 1 made of perforated plates. When the pressure inside the screen casing 1 is high, the amount of sludge that moves to the outside of the screen casing 1 increases. As a result, much sludge adheres to the outer surface of the screen casing 1 . A high pressure inside the screen casing 1 means a large amount of plug cake, that is, a low rotation speed of the second screw 4 .

Also, the flow rate of the filtrate discharged through the screen casing 1 made of perforated plates varies depending on the amount of plug cake. Specifically, when the amount of plug cake is large (that is, when the rotation speed of the second screw 4 is low), more filtrate flows out through the screen casing 1 .

Therefore, the rotation speed of the second screw 4 changes the amount of sludge adhering to the outer surface of the screen casing 1 and the flow rate of filtrate flowing out from the screen casing 1 . The operator visually confirms the amount of sludge and the flow rate of the filtrate, and determines the optimum rotation speed of the second screw 4 based on experience. The rotational speed of the second screw 4 determined by the operator is the correct label (or objective variable). At the same time, the imaging device 50 produces an image of the outer surface of the screen casing 1 . Sludge and filtrate that have moved to the outer surface of the screen casing 1 appear on the image of the outer surface of the screen casing 1 . The image of the outer surface of the screen casing 1 is combined with the rotational speed of the second screw 4 determined by the operator. The training data includes multiple combinations of images of the outer surface of the screen casing 1 and corresponding rotation speeds of the second screw 4 thus created.

The motion control unit 6 uses training data to construct a model according to a machine learning algorithm. Examples of machine learning algorithms include a support vector regression method, a deep learning method, a random forest method, a decision tree method, and the like, and the deep learning method is used in this embodiment. A deep learning method is a learning method based on a neural network in which intermediate layers (also called hidden layers) are multi-layered. In this specification, machine learning using a neural network composed of an input layer, two or more intermediate layers, and an output layer is referred to as deep learning.

Building a model using deep learning is performed using training data containing images of the outer surface of the screen casing 1 and the corresponding rotational speeds of the second screw 4 . Building a model according to a machine learning algorithm involves optimizing parameters such as neural network weights. A program for constructing the model according to the machine learning algorithm is pre-stored in the storage device 6a.

The model constructed in this way, that is, the learned model is stored in the storage device 6a. During operation of the screw press, the imaging device 50 generates an image of the outer surface of the screen casing 1 and sends the image to the motion control section 6 . The motion control unit 6 inputs the image to the model. The motion control unit 6 performs calculations according to the algorithm defined in the model, and determines the rotation speed of the second screw 4, which is the rotation speed output from the model. The motion control unit 6 issues a command to the second rotating mechanism 20 to rotate the second screw 4 at the determined rotational speed.

According to this embodiment, the optimum rotational speeds of the first screw 3 and the second screw 4 are determined based on the sludge level at the inlet 2 and the image of the outer surface of the screen casing 1 . The motion control unit 6 issues commands to the first rotating mechanism 7 and the second rotating mechanism 20 to rotate the first screw 3 and the second screw 4 at the determined rotational speeds, respectively.

The operation control section 6 has at least one computer. For example, the operation control unit 6 may be an edge server connected to the imaging device 50 and the level measuring device 40 via a communication line, or may be an edge server connected to the imaging device 50 and the level measuring device 40 via a communication network such as the Internet or a local area network. It may be a cloud server connected to The operation control unit 6 may be a combination of multiple servers. For example, the operation control unit 6 may be a combination of an edge server and a cloud server connected to each other by a communication network such as the Internet or a local area network, or a combination of multiple servers not connected by a communication network.

Next, a method of operating the screw press shown in FIG. 1 will be described with reference to FIGS. 3 to 5. FIG. 3 to 5 are diagrams for explaining the operation of the screw press shown in FIG. 1. FIG.

As shown in FIG. 3 , the motion control unit 6 drives the first rotating mechanism 7 to rotate the first screw 3 while the second screw 4 is stopped. Next, sludge (suspension) is introduced into the screen casing 1 through the inlet 2 . Sludge introduced from the inlet 2 is transferred toward the second screw 4 (that is, in the transfer direction D) by the rotating first screw blades 3B.

In the dewatering area 1A where the first screw 3 is arranged, the cross-sectional area of the space through which the sludge is transferred gradually decreases along the transfer direction D. Therefore, the sludge is compressed as it is transferred through the dewatering area 1A, and the water contained in the sludge is filtered by the screen casing 1. FIG. Since the layer of sludge deposited on the inner surface of the screen casing 1 is scraped off by the rotating first screw blades 3B, the inner surface (filtration surface) of the screen casing 1 in the dewatering area 1A is always maintained in good condition.

While the sludge is being transported through the dewatering area 1A of the screen casing 1, the sludge is dewatered into a cake and sent to the plug forming area 1B where the second screw 4 is arranged. As shown in FIG. 3, at the beginning of operation, the second screw 4 is not rotating (that is, stopped), so the cake in the plug forming area 1B is not discharged to the discharge chute 33, and the plug forming area 1B is not discharged. Stay in area 1B. The cake gradually accumulates on the second screw 4 and is pressed against the second screw blades 4B by the sludge transferred from the dewatering area 1A to the plug forming area 1B (hereinafter referred to as "subsequent cake"). The cake in the plug forming region 1B is squeezed by being prevented from moving by the second screw blade 4B, and becomes a cake with a low moisture content. This low moisture content cake forms a plug cake that impedes subsequent cake migration. A plug cake formed around the second screw shaft 4A applies back pressure to the subsequent cake, which is further squeezed. The water separated from the plug cake in the plug forming area 1B is collected by the filtrate receiver 38 and discharged from the screw press through the drain 39.

As the operation of the screw press continues, the plug cake is uniformly formed over the entire circumference of the second screw shaft 4A. As a result, as shown in FIG. 3, a plug cake is formed around the second screw shaft 4A that reliably blocks the subsequent cake. Therefore, even when the subsequent cake has a high moisture content, the subsequent cake can be reliably blocked by the plug cake formed in the plug forming region 1B, so that the subsequent cake can be prevented from flowing sideways. This "single flow" means that the succeeding cake, which has a higher moisture content than the plug cake, passes through the plug forming region 1B as it is and is discharged to the discharge chute 33.

As shown in FIG. 4, after the plug cake is formed, the motion controller 6 determines the rotational speed of the first screw 3 based on the level of sludge at the inlet 2 . Furthermore, the motion control unit 6 inputs the image of the outer surface of the screen casing 1 to the model, and determines the rotation speed of the second screw 4, which is the rotation speed output from the model. Then, the motion control unit 6 issues a command to the first rotating mechanism 7 and the second rotating mechanism 20 to rotate the first screw 3 and the second screw 4 at the determined rotational speeds. The direction of rotation of the second screw 4 is opposite to the direction of rotation of the first screw 3 .

The sludge is introduced into the screen casing 1 from the inlet 2 while rotating the first screw 3 and the second screw 4 at the determined rotational speeds. The first screw 3 presses the sludge against the plug cake and squeezes the sludge, while the second screw 4 taps off the other part of the plug cake while forming part of the plug cake with subsequent cakes. Send (ie, eject) to the ejection chute 33 . In this way, the formation of the plug cake and the discharge of the plug cake are continuously performed, so that the screw press can be operated with the plug cake always present in the plug forming region 1B.

In this embodiment, by rotating the second screw 4 in a direction opposite to the direction of rotation of the first screw 3 , it is possible to remove the low moisture content plug cake from the screen casing 1 . Furthermore, according to this embodiment, it is not necessary to provide a resistor such as a back pressure plate at the discharge side end of the screen casing 1 . Therefore, the plug cake can be smoothly discharged from the screen casing 1 to the discharge chute 33 . Furthermore, since a back pressure plate and an operating mechanism for the back pressure plate are not required, the screw press can be manufactured at low cost.

The pitch of the second screw blades 4B of the second screw 4 is smaller than the pitch of the first screw blades 3B of the first screw 3 . When the pitch of the second screw blades 4B is made smaller than the pitch of the first screw blades 3B in this way, the transfer distance of the plug cake discharged to the discharge chute 33 during one rotation of the second screw 4 is shortened. , it becomes possible to finely adjust the back pressure applied to the cake in the dewatering area 1A.

In a general uniaxial screw press, if the plug cake squeezed into a cylindrical shape becomes too hard, the hardened plug cake clogs the screen casing and cannot be discharged from the screen casing. Additionally, this hardened plug cake co-rotates with the screw. As a result, the operation of the screw press cannot be continued. In the twin screw press of this embodiment, the winding direction of the second screw blades 4B of the second screw 4 is opposite to the winding direction of the first screw blades 3B of the first screw 3 . Therefore, when discharging the plug cake formed in the plug forming area 1B to the discharge chute 33, the second screw 4 is rotated in the direction opposite to the direction of rotation of the first screw 3, as shown in FIG. When the cake is pressed against the plug cake by the first screw 3 rotating in the opposite direction to the second screw 4, a force is applied to the plug cake in the direction opposite to the rotating direction of the second screw 4.例文帳に追加As a result, co-rotation between the plug cake in the plug forming region 1B and the second screw 4 and/or co-rotation between the cake in the dehydration region 1A and the first screw 3 is prevented, so that a high back pressure is applied to the sludge. It becomes possible to operate the screw press while adding

As shown in FIG. 5, the second screw 4 may be temporarily rotated in the same direction as the first screw 3 . When the second screw 4 is rotated in the same direction as the first screw 3, the plug cake formed in the plug forming area 1B is pushed out toward the dewatering area 1A, and a larger back pressure can be applied to the cake in the dewatering area 1A. can. As a result, the sludge dewatering efficiency can be improved.

In one embodiment, the winding direction of the second screw blade 4B may be the same as the winding direction of the first screw blade 3B. In this case, the second screw 4 is rotated in the same direction as the first screw 3 when sending out the sludge introduced from the inlet 2 to the discharge chute 33 .

The screw press of the embodiment described above is used to separate liquid water from sludge, which is an example of a suspension. may be used. For example, the screw press according to the above-described embodiment can be used for processing foods such as fruits and oils, and for processing industrial products such as waste paper recycling. In food processing, screw presses are used to press raw materials (suspensions), such as fruits, seeds, etc., to separate liquids, such as fruit juices, oils, etc. from the raw materials. Waste paper recycling involves mixing the waste paper with liquids such as water and chemicals to loosen the waste paper into fibrous materials. A screw press is used to squeeze a mixture (suspension) of fibrous material and liquid to separate the fibrous material from the mixture. Suspensions include suspensions before concentration and concentrated suspensions.

The above-described embodiments are described for the purpose of enabling a person having ordinary knowledge in the technical field to which the present invention belongs to implement the present invention. Various modifications of the above embodiments can be made by those skilled in the art, and the technical idea of the present invention can be applied to other embodiments. Accordingly, the present invention is not limited to the described embodiments, but is to be construed in its broadest scope in accordance with the technical spirit defined by the claims.

1 Screen casing (filter cylinder)
1A dewatering area 1B plug forming area 2 inlet 3 first screw 3A first screw shaft 3B first screw blade 4 second screw 4A second screw shaft 4B second screw blade 6 operation control unit 7 first rotating mechanism 8 closing wall REFERENCE SIGNS LIST 10 water seal device 20 second rotation mechanism 33 discharge chute 38 filtrate receiver 39 drain 40 level measuring device 50 imaging device

Claims (2)

a filter cylinder having an inlet into which the suspension is introduced;
a first screw and a second screw arranged in the filter cylinder for transporting the suspension in a predetermined transport direction;
a first rotating mechanism for rotating the first screw;
a second rotating mechanism that rotates the second screw independently of the first screw;
an imaging device for generating an image of the outer surface of the filter tube;
a level measuring device for measuring the level of the suspension at the inlet;
an operation control unit that issues commands to the first rotation mechanism and the second rotation mechanism to control the rotation speed of the first screw and the rotation speed of the second screw;
The second screw is arranged downstream of the first screw in the transport direction,
The operation control unit controls the rotation speed of the first screw so that the measured value of the suspension level is maintained within a predetermined range, and adjusts the rotation speed of the second screw based on the image. A screw press configured to determine. The motion control unit has a storage device storing a model constructed by machine learning, and the motion control unit inputs the image to the model and performs calculation according to the algorithm defined in the model. and determining a rotational speed of the second screw that is the rotational speed output from the model.

Images